In addition to 24 hour availability, two major advantages to shopping online are that there is generally more selection online than in a brick and mortar store and shopping online is more convenient than going to a store. Stores have to pay for the space in which they display their goods. They have to have relatively large spaces so that their goods are presented attractively and in a way that is easily accessible. They have to be in good locations. All of this means that it is expensive to have a large store. Because it is expensive to have a large store, stores try to stock only the items that really sell well. By contrast, online stores can stock a large variety of items. They only have to pay for warehouse space, which is relatively cheap because goods can be packed into the warehouse and the warehouse can be located in an undesirable, low-rent area. For these reasons, online retailers tend to have much more variety available.
Shopping online is also more convenient. A person does not have to leave their home to do this. They can do it while the baby is napping or while they are on their lunch break. They do not have to get dressed or drive across town.
Of course, a major disadvantage of online shopping is the inability to actually touch and look at items. You cannot try on clothes. You cannot play with a camera to see if it feels good to you. These are things that can only be done in person. The fact that you cannot do these things when shopping online is a definite disadvantage.